The Impact of Preexisting Myocardial Remodeling on Ventricular Function Early after Tetralogy of Fallot Repair

Background: Twenty-three patients (median age 23 months) who underwent Fallot`s tetralogy repair were investigated prospectively to detect a possible association between histopathologic myocardial remodeling and echocardiographic findings of systolic or diastolic ventricular dysfunction. Methods: Intraoperatively resected infundibular bands and subendocardial biopsy samples from the right ventricle (RV) and left ventricle were obtained for histopathologic evaluation. Tissue Doppler echocardiographic interrogation of the ventricles was performed before surgery and in the postoperative period. Results: Histopathologic data revealed hypertrophy of the RV cardiomyocytes and increased interstitial collagen in both ventricles. Mean values of RV isovolumic acceleration decreased significantly at the third evaluation compared with the preoperative values (P = .006). RV myocardial fibrosis greater than 8.3% was associated with a probability of altered E` of at least 0.7 (odds ratio = 2.31). Conclusion: Preoperative histologic myocardial remodeling influenced the postoperative RV function in this group of patients with late repair. Further studies are necessary to evaluate the myocardium in younger patients and to define its influence in the long-term follow-up. (J Am Soc Echocardiogr 2010;23:912-8.)

Chronic alcoholism associated with diabetes impairs erectile function in rats

OBJECTIVE To investigate the effects of chronic ethanol consumption and diabetes on nitric oxide (NO)-mediated relaxation of cavernosal smooth muscle (CSM). MATERIAL AND METHODS Male Wistar rats were divided into four groups: control, isocaloric, diabetic and ethanol-diabetic. The CSMs were mounted in organ chambers for measurement of isometric tension. Contraction of the strips was induced by electrical field stimulation (EFS, 1-32 Hz) and phenylephrine. We also evaluated the effect of ethanol consumption on the relaxation induced by acetylcholine (ACh; 0.01-1000 mu mol/L), sodium nitroprusside (SNP, 0.01-1000 mu mol/L) or EFS (1-32 Hz) in strips pre-contracted with phenylephrine (10 mu mol/L). Immunoexpression of endothelial NO synthase (eNOS) and inducible NOS (iNOS) was also accessed. RESULTS The endothelium-dependent relaxation induced by ACh was decreased in CSM from ethanol-diabetic rats when compared with the controls, with a mean (sem) of 21 (4) vs 37 (2)%. Similarly, the potency and maximal responses induced by SNP were reduced in the ethanol-diabetic [3.97 (0.38) and 85 (1)%, respectively] and diabetic groups [3.78 (0.56) and 81 (2)%, respectively] when compared with the controls [5.3 (0.22) and 90 (3)%, respectively] and isocaloric [5.3 (0.19) and 92 (1)%, respectively] groups. Noradrenergic nerve-mediated contractions of CSM in response to EFS were increased in rats from ethanol-diabetic and diabetic groups when compared with the control and isocaloric groups. Conversely, there were no differences in EFS-induced relaxation among the groups. The immunostaining assays showed overexpression of eNOS and iNOS in the CSM from diabetic and ethanol-diabetic rats when compared with the control and isocaloric rats. CONCLUSION There was an impairment of relaxation of CSM from ethanol-diabetic and diabetic rats that involved a decrease in the NO-cyclic guanosine monophosphate signalling pathway by endothelium-dependent mechanisms accompanied by a change in the CSM contractile sensitivity.

Short-Term Effects of Hydroxyethylstarch Resuscitation on Systemic and Regional Hemodynamics and Metabolism in a Brain-Dead Canine Model

Background. Hydroxyethylstarch (HES) is a synthetic polymer of glucose that has been suggested for therapeutic use in long-term plasma expansion. The aim of this study was to test the hypothesis that the infusion of a small volume of HES may provide benefits in systemic and regional hemodynamics and metabolism in a brain-dead canine model compared with large volume crystalloid resuscitation. Methods. Fourteen mongrel dogs were subjected to a brain-death protocol by consecutive insufflations of a balloon catheter in the epidural space. One hour after induction of brain-death, the animals were randomly assigned to two groups: NS (0.9% NaCl, 33mL/kg), and HES (6% HES 450/0.7, 17mL/Kg). Systemic and regional hemodynamics were evaluated using Swan-Ganz, ultrasonic flowprobes, and arterial catheters. Serial blood samples were collected for blood gas, electrolyte, and serum chemistry analysis. Systemic, hepatic, and splanchnic O(2)-derived variables were also calculated. Results. Epidural balloon insufflations induced a significant increase in mean arterial pressure, cardiac output (MAP and CO, respectively), regional blood flow, and systemic vascular resistance. Following the hyperdynamic phase, severe hypotension with normalization of systemic and regional blood flow was observed. Fluid resuscitation induced a prompt increase in MAP, CO, and portal vein blood flow, and a significant reduction in systemic and pulmonary vascular resistance. There were no differences between groups in metabolic indices, liver function tests (LFTs), or renal function tests. HES was more effective than NS in restoring cardiac performance in the first 2h after fluid resuscitation (P < 0.05). Both tested solutions partially and temporarily restored systemic and regional oxygen delivery. Conclusion. Small volumes of 6% HES 450/0.7 improved cardiovascular performance and provided the same regional hemodynamic and metabolic benefits of large volumes of isotonic crystalloid solutions. (C) 2011 Elsevier Inc. All rights reserved.

Effects of type II pyrethroid cyhalothrin on rat innate immunity: A flow cytometric study

Synthetic type II pyrethroids induce anxiety, immunosuppresion or, alternatively, immunostimulatory effects in laboratory animals. Macrophages and neutrophils are known to be key elements in cellular immune responses. The present study was designed to investigate the in vivo effects of cyhalothrin (1.0 and 3.0 mg/kg/once daily for 7 days) on macrophage and neutrophil activities, using a flow cytometry method. Results showed that cyhalothrin treatment decreased the percentage and intensity of phagocytosis performed by macrophages, but did not alter these parameters in neutrophils: and also decreased basal neutrophil oxidative burst and increased S. aureus-induced neutrophil oxidative burst, but did not alter these responses in macrophages. The present results are discussed in the light of a possible indirect action of cyhalothrin on macrophage and neutrophil activities via hypothalamic pituitary adrenal (HPA) axis activation. A possible direct effect of cyhalothrin on macrophage and neutrophil activities is also considered. (C) 2008 Elsevier B.V. All rights reserved.

Ovarian function in Nelore (Bos taurus indicus) cows after post-ovulation hormonal treatments

Maternal recognition of pregnancy in the cow requires successful signaling by the conceptus to block luteolysis. Conceptus Growth and function depend on an optimal uterine environment, regulated by luteal progesterone. The objective of this study was to test strategies to optimize luteal function, as well as prevent a dominant follicle from initiating luteolysis. Nelore (Bos taurus indicus) beef cows (n = 40) were submitted to a GnRH/PGF(2 alpha)/GnRH protocol. Cows that ovulated from a dominant ovarian follicle (ovulation = Day 0) were allocated to receive: no additional treatment (Gc; n = 7); 3000 IU of hCG on Day 5 (G(hCG); n = 5); 5 mg of estradiol-17 beta on Day 12 (G(E2); n = 6); or 3000 IU of hCG on Day 5 and 5 mg of estradiol-17 beta on Day 12 (G(hCG/E2); n = 5). Ultrasonographic imaging of the ovaries, assessment of plasma progesterone concentration, and detection of estrus were done daily from Day 5 to the day of subsequent ovulation. Treatment with hCG induced an accessory CL, increased CL volume, and plasma progesterone concentration throughout the luteal phase (P < 0.01). Estradiol-17 beta induced atresia and recruitment of a new wave of follicular growth; it eliminated a potentially estrogen-active, growing ovarian follicle within the critical period for maternal recognition of pregnancy, but it also hastened luteolysis (Days 16 or 17 vs. Days 18 or 19 in non-treated cows). In conclusion, the approaches tested enhanced luteal function (hCG) and altered ovarian follicular dynamics (estradiol-17 beta), but were unable to extend the life-span of the CL in Nelore cows. (c) 2008 Elsevier Inc. All rights reserved.

Effects that bovine sperm cryopreservation using two different extenders has on sperm membranes and chromatin

The process of cryopreservation impairs sperm cell function, potentially leading to a reduction in fertility. The objectives of the present study were to evaluate the effects that cryopreservation using two different extenders has on sperm motility and mitochondrial function, as well as on the integrity of plasma membranes, acrosomal membranes and chromatin, using practical and objective techniques. The focus of the present study was to identify correlations between alterations in sperm membranes and sperm motility in cryopreserved bovine spermatozoa. Seven ejaculates were collected from eight Simmental bulls (n = 56). After collection, semen volume and concentration were assessed for purposes of dilution. Sperm motility was evaluated subjectively and by computer-assisted semen analysis, morphological characteristics were evaluated by differential interference microscopy, the integrity of plasma and acrosomal membranes, as well as mitochondrial function, were determined using a combination of fluorescent probes containing fluorescein isothiocyanate-Pisum sativum agglutinin, propidium iodide or 5,5`,6,6`-tetrachloro-1,1`,3,3`-tetraethylbenzimidazolearbocyanine iodide. Chromatin integrity was evaluated using the acridine orange technique. The semen was subsequently divided into two aliquots and diluted with one of two extenders (Bioxcell(R) or Botu-Bov(R)), after which both were packaged in 0.5 mL straws and frozen using an automated system. Two straws of semen from each treatment were thawed, and the semen parameters were evaluated as described above. Cryopreservation of sperm reduced motility, damaging plasma and acrosomal membranes, as well as decreasing mitochondrial function. The Botu-Bov(R) extender was more effective in preserving sperm motility and membrane integrity than was the Bioxcell(R) extender. (C) 2007 Elsevier B.V. All rights reserved.

Cell cycle and apoptosis in normal and cloned bovine near-term placentae

The bovine maternal epithelium is composed of cuboidal cells interspersed with low columnar cells having centrally located nuclei. Bovine trophoblast is composed of two cell types: mononuclear trophoblastic and giant trophoblastic cells that can have two or more nuclei. Number of apoptotic cells and proliferative cells are variable in both cell populations. This study compared tissue growth and apoptosis by flow cytometry in the cell population found at distinct placental regions (central region of placentomes, <= 1-cm microplacentomes and the interplacentomal region) between normal and cloned near-term bovine pregnancies. After a morphological comparison between regions and groups (controls vs. clones), a lesser proportion of diploid to tetraploid cells was observed in the central region of placentomes and in microplacentomes from cloned-derived pregnancies. In addition, cloned animals had a fewer apoptotic cells in the central region of the placentome and in interplacentomal region and a greater proliferative capacity in all regions (cells in G(2)/M) near term as opposed to control animals. These results may reveal the existence of a relationship between such changes in the proportions of uterine and trophoblastic epithelial cells at the end of pregnancy and normal placental function. This could be related to faulty placentation in early pregnancy, placental insufficiency during pregnancy or lack of placental and/or fetal maturation in late pregnancy, which may contribute to someof the abnormalities after in vitro embryo manipulations, such as poor preparation and initiation of parturition, prolonged gestation and lesser post-natal survival in some cloned animals. (C) 2008 Elsevier B.V. All rights reserved.

Hepatic function evolution in dogs anesthetized with Zolazepam/Tiletamine

The hepatic effects of the anesthetic association zolazepam/tiletamine were investigated in dogs by analyzing the serum concentration of hepatic enzymes. Ten healthy dogs were divided into two groups of five, group I (GI) and group II (GII). The animals of GI received a single dose of 6,6 mg/kg of zolazepam/tiletamine, by intramuscular (IM) injection. GII dogs received 6,6 mg/kg of zolazepam/tiletamine by the IM route; after a period of 50 - 80 minutes the animals received two additional doses (3,3 mg/kg) by intravenous administration[SAH1]. The hepatic function were analyzed by monitoring the serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl-transferase (GGT). Four blood samples were collected in different moments during the analyses: M0, before the first application of the drug; and M1 to M4. M1 through M3 was collected with intervals of 20 minutes before M0, while M4 was obtained 24 hours after M1. The normality of the obtained results was analyzed by Kolmogorov-Smirnov Test; while the Tukey`s test compared the means, using a level of significance of 5% for both statistical analyses. The mean values of all enzymes evaluated were within normal limits for both experimental groups, without any significant statistical alteration being observed between and within these groups. These results demonstrated that the association of zolazepam/tiletamine at the dosage of 6.6 mg/kg, followed by two applications additional of 3.3 mg/kg resulted in elevation of the evaluated hepatic enzymes without exceeding the physiologic values. Additionally, a single application of 6.6 mg/kg of zolazepam/tiletamine by the intramuscular route resulted in lower values when compared to three applications.

Poor ovarian response in patients younger than 35 years: Is it also a qualitative decline in ovarian function?

Objective. To investigate whether poor response to controlled ovarian stimulation (COS) is due to a qualitative decline in ovarian function. Methods. This retrospective cohort study included 436 patients younger than 35-years old, undergoing COS for intracytoplasmic sperm injection (ICSI). Patients with four or fewer MII oocytes after COS (poor-responder group, PR, n = 52) were age-matched with normoresponder patients (NR, n = 364). Results. Although similar duration of stimulation (10.5 +/- 0.4 and 9.3 +/- 0.8 days; p = 0.1358), increased doses of gonadotrophins (2510 +/- 865 and 2253 +/- 572 IU; p = 0.0061) were used in the PR. The results show a increased chance of cycle ending of PR (PR: 26.9% and NR: 3.1%; p < 0.0001). Although the lower total number of oocytes retrieved (2.4 +/- 1.4 and 16.2 +/- 9.3; p < 0.0001), equal rate of fertilization (70.2% and 72.0%, p = 0.1190) and high quality embryos were obtained (50.0% and 45.2%; p = 0.4895), resulting in similar implantation (14.5% and 19.7%; p = 0.2246) and abortion (10.0% and 15.4%; p = 1.00) rates, respectively. A trend towards increased pregnancy rate per embryo transfer in NR group was noted (PR: 26.3% and NR: 42.2%; p = 0.0818). Conclusions. Low ovarian response could be associated mainly with a quantitative rather than a qualitative decline in ovarian function. Therefore, even if the ovarian response to stimulation is low, patients aged <= 35 years should process to oocyte retrieval.